Androgens and estrogens are known to play a role in learning processes in several species (e.g., Wolf, Preut et al. 2000; Frick and Berger-Sweeney 2001; Frye and Rhodes 2002) but a majority of the research on the topic has focused on behaviors that are unrelated to reproductive activity (e.g., spatial memory, visual memory, response learning, fear learning, verbal fluency in humans). The mechanism by which steroid hormones interact with experience to influence sexual behavior is an intriguing phenomenon from physiological, ecological, and human health perspectives but has received relatively little attention. The goal of this proposal is to develop an experimental paradigm that will clearly demonstrate acquired mate preference in laboratory mice. Experiment 1 will establish whether C57BL/6 mice acquire mate preferences during sexual organization through a process of sexual imprinting. Experiment 2 will utilize a classical conditioning paradigm with adult male mice to determine whether mate preferences can be established by pairing a novel odor with sexual opportunity. Once developed, the paradigm will serve as a foundation for an investigation of the role of sex hormones in the development and expression of learned sexual behaviors.